Customer Background

A French diesel workshop removed an injector after finding combustion residue around the injector area.

The component had been operating with evidence of leakage around the lower sealing interface.

Why Replacing the Seal Was Not Enough

Combustion leakage can leave carbon deposits inside the injector bore and around the seating area.

Installing a new sealing washer without inspecting the seat may allow the problem to return.

Repair Process

The workshop removed loose deposits using the service method suitable for the engine.

The injector seat and bore were inspected for damage.

The technician avoided removing unnecessary material from the cylinder head because excessive machining can alter injector position.

The new sealing components were then installed according to the engine service procedure.

Final Verification

After reassembly, the workshop checked the injector area during engine operation for renewed leakage.

The repair was not considered complete until the sealing interface had been verified.

Case Conclusion

This France workshop case demonstrates why injector seat preparation is part of repairing combustion leakage.

Replacing the injector or washer alone cannot compensate for an unsuitable seating surface.